Relax permissions checks on dbsize functions, per discussion.  Revert out all checks for individual-table-size functions, since anyone in the database could get approximate values from pg_class.relpages anyway.  Allow database-size to users with CONNECT privilege for the target database (note that this is granted by default).  Allow tablespace-size if the user has CREATE privilege on the tablespace (which is *not* granted by default), or if the tablespace is the default tablespace for the current database (since we treat that as implicitly allowing use of the tablespace).
Relax permissions checks on dbsize functions, per discussion.  Revert out all
checks for individual-table-size functions, since anyone in the database could
get approximate values from pg_class.relpages anyway.  Allow database-size to
users with CONNECT privilege for the target database (note that this is
granted by default).  Allow tablespace-size if the user has CREATE privilege
on the tablespace (which is *not* granted by default), or if the tablespace is
the default tablespace for the current database (since we treat that as
implicitly allowing use of the tablespace).

xuegang/gpdb,rvs/gpdb,adam8157/gpdb,ahachete/gpdb,janebeckman/gpdb,lintzc/gpdb,rvs/gpdb,postmind-net/postgres-xl,chrishajas/gpdb,ahachete/gpdb,kaknikhil/gpdb,zeroae/postgres-xl,rvs/gpdb,adam8157/gpdb,adam8157/gpdb,CraigHarris/gpdb,Chibin/gpdb,cjcjameson/gpdb,kmjungersen/PostgresXL,50wu/gpdb,Chibin/gpdb,chrishajas/gpdb,jmcatamney/gpdb,zeroae/postgres-xl,xinzweb/gpdb,janebeckman/gpdb,royc1/gpdb,techdragon/Postgres-XL,Postgres-XL/Postgres-XL,chrishajas/gpdb,ashwinstar/gpdb,kmjungersen/PostgresXL,kaknikhil/gpdb,oberstet/postgres-xl,yuanzhao/gpdb,kaknikhil/gpdb,lisakowen/gpdb,CraigHarris/gpdb,kaknikhil/gpdb,jmcatamney/gpdb,CraigHarris/gpdb,xuegang/gpdb,yazun/postgres-xl,jmcatamney/gpdb,rvs/gpdb,Chibin/gpdb,lintzc/gpdb,kmjungersen/PostgresXL,yuanzhao/gpdb,ovr/postgres-xl,janebeckman/gpdb,ashwinstar/gpdb,tpostgres-projects/tPostgres,ovr/postgres-xl,edespino/gpdb,lintzc/gpdb,snaga/postgres-xl,greenplum-db/gpdb,lisakowen/gpdb,arcivanov/postgres-xl,edespino/gpdb,jmcatamney/gpdb,rvs/gpdb,zaksoup/gpdb,xinzweb/gpdb,CraigHarris/gpdb,zeroae/postgres-xl,pavanvd/postgres-xl,techdragon/Postgres-XL,ahachete/gpdb,rvs/gpdb,janebeckman/gpdb,0x0FFF/gpdb,greenplum-db/gpdb,CraigHarris/gpdb,tpostgres-projects/tPostgres,royc1/gpdb,Quikling/gpdb,royc1/gpdb,zaksoup/gpdb,postmind-net/postgres-xl,ovr/postgres-xl,edespino/gpdb,adam8157/gpdb,lisakowen/gpdb,techdragon/Postgres-XL,lintzc/gpdb,royc1/gpdb,cjcjameson/gpdb,Quikling/gpdb,yazun/postgres-xl,arcivanov/postgres-xl,0x0FFF/gpdb,CraigHarris/gpdb,Postgres-XL/Postgres-XL,xinzweb/gpdb,janebeckman/gpdb,Chibin/gpdb,ahachete/gpdb,cjcjameson/gpdb,edespino/gpdb,xinzweb/gpdb,cjcjameson/gpdb,zeroae/postgres-xl,Quikling/gpdb,zaksoup/gpdb,oberstet/postgres-xl,pavanvd/postgres-xl,greenplum-db/gpdb,ashwinstar/gpdb,yuanzhao/gpdb,yuanzhao/gpdb,arcivanov/postgres-xl,50wu/gpdb,postmind-net/postgres-xl,chrishajas/gpdb,snaga/postgres-xl,kaknikhil/gpdb,chrishajas/gpdb,kaknikhil/gpdb,xuegang/gpdb,techdragon/Postgres-XL,tpostgres-projects/tPostgres,ovr/postgres-xl,greenplum-db/gpdb,pavanvd/postgres-xl,rvs/gpdb,cjcjameson/gpdb,adam8157/gpdb,0x0FFF/gpdb,lintzc/gpdb,ahachete/gpdb,Quikling/gpdb,xuegang/gpdb,Postgres-XL/Postgres-XL,Chibin/gpdb,yuanzhao/gpdb,edespino/gpdb,adam8157/gpdb,pavanvd/postgres-xl,chrishajas/gpdb,edespino/gpdb,zaksoup/gpdb,rvs/gpdb,ahachete/gpdb,zaksoup/gpdb,xuegang/gpdb,yazun/postgres-xl,tpostgres-projects/tPostgres,kaknikhil/gpdb,greenplum-db/gpdb,xinzweb/gpdb,royc1/gpdb,cjcjameson/gpdb,royc1/gpdb,xinzweb/gpdb,jmcatamney/gpdb,50wu/gpdb,xinzweb/gpdb,lisakowen/gpdb,zaksoup/gpdb,xuegang/gpdb,janebeckman/gpdb,royc1/gpdb,yuanzhao/gpdb,edespino/gpdb,ashwinstar/gpdb,kaknikhil/gpdb,Chibin/gpdb,cjcjameson/gpdb,oberstet/postgres-xl,50wu/gpdb,zeroae/postgres-xl,50wu/gpdb,0x0FFF/gpdb,xuegang/gpdb,Quikling/gpdb,kmjungersen/PostgresXL,arcivanov/postgres-xl,ashwinstar/gpdb,pavanvd/postgres-xl,yuanzhao/gpdb,Chibin/gpdb,adam8157/gpdb,jmcatamney/gpdb,ashwinstar/gpdb,jmcatamney/gpdb,lisakowen/gpdb,cjcjameson/gpdb,rvs/gpdb,CraigHarris/gpdb,yazun/postgres-xl,postmind-net/postgres-xl,chrishajas/gpdb,kmjungersen/PostgresXL,cjcjameson/gpdb,Quikling/gpdb,janebeckman/gpdb,lintzc/gpdb,rvs/gpdb,edespino/gpdb,yazun/postgres-xl,0x0FFF/gpdb,janebeckman/gpdb,tpostgres-projects/tPostgres,Quikling/gpdb,50wu/gpdb,lintzc/gpdb,yuanzhao/gpdb,CraigHarris/gpdb,lisakowen/gpdb,snaga/postgres-xl,chrishajas/gpdb,greenplum-db/gpdb,Quikling/gpdb,arcivanov/postgres-xl,janebeckman/gpdb,lintzc/gpdb,zaksoup/gpdb,oberstet/postgres-xl,yuanzhao/gpdb,edespino/gpdb,cjcjameson/gpdb,xinzweb/gpdb,techdragon/Postgres-XL,lintzc/gpdb,lisakowen/gpdb,CraigHarris/gpdb,Postgres-XL/Postgres-XL,adam8157/gpdb,ashwinstar/gpdb,Chibin/gpdb,50wu/gpdb,Quikling/gpdb,jmcatamney/gpdb,snaga/postgres-xl,50wu/gpdb,yuanzhao/gpdb,janebeckman/gpdb,Chibin/gpdb,lisakowen/gpdb,ahachete/gpdb,Postgres-XL/Postgres-XL,0x0FFF/gpdb,xuegang/gpdb,snaga/postgres-xl,ashwinstar/gpdb,oberstet/postgres-xl,arcivanov/postgres-xl,postmind-net/postgres-xl,kaknikhil/gpdb,0x0FFF/gpdb,ahachete/gpdb,Quikling/gpdb,xuegang/gpdb,greenplum-db/gpdb,royc1/gpdb,zaksoup/gpdb,Chibin/gpdb,ovr/postgres-xl,edespino/gpdb,greenplum-db/gpdb,0x0FFF/gpdb,kaknikhil/gpdb